A little more detail would help, os10, 9, are you using stuffit to open it or a diffrent program? Do you get any sort of error message? But anyway if you have it on a cd or some other sort of back up it never hurts to delete that one and try agian. Other then that i dont know what to say, ive had various files on cd's that after awhile just got corrupted some how, and i either couldnt transfer it from the cd or it just didnt work.
